Bevel locking system for a sliding compound miter saw

ABSTRACT

A power tool includes a table. A shaft is fixedly secured to the table. The power tool also has a support housing supporting a motor and a working tool driven by the motor. The support housing is disposed on the shaft adjacent to the table and is axially movable along the shaft and laterally pivotable about an axis of rotation. In addition, the power tool has a locking mechanism for locking the support housing at a predetermined lateral position, wherein the locking mechanism includes a handle disposed on the shaft. The handle is rotatable in two directions with respect to the shaft, such that rotation of the handle on the shaft urges the support housing into locking contact with the table. A method for operating the power tool is also disclosed herein.

This application is a continuation-in-partof U.S. Ser. No. 08/761,730,filed Dec. 5, 1996; which claims the benefit of U.S. ProvisionalApplication No. 60/008,512, filed Dec. 15, 1995, now abandoned.

FIELD OF THE INVENTION

The present invention relates to compound miter saws or other poweroperated equipment or machinery utilizing a cutter for performingworking operations on a workpiece. More particularly, the presentinvention relates to improvements in the bevel lock mechanism for thebevel adjustment for such power operated equipment.

BACKGROUND OF THE INVENTION

Saws and other apparatuses designed for cutting or performing otherworking operations on a workpiece typically require adjustmentmechanisms for moving the saw blade or cutting tool into an angularrelationship to the workpiece. Examples of such equipment includecross-cut compound miter saws which are adapted for allowing the user toselectively move the saw blade into any of a number of positions ormodes for square cutting, miter cutting, bevel cutting, or compoundmiter cutting where a combination miter angle and bevel angle are cut.In addition, some operations, such as dado cutting or shapingoperations, for example, require the use of saw blades or other cuttingor working devices of different shapes or sizes to be substituted forone another in order to perform the desired operation on the workpiece,whether the workpiece is composed of wood, plastic, metal or othermaterials.

In order to allow for the adjustment in the miter and the bevel angle,the saw blade, cutter or other working device is angularly adjustablewith respect to a horizontal base and a vertical fence against which theworkpiece is positioned. The miter adjustment allows the saw blade,cutter or other working device to move angularly with respect to thevertical fence while maintaining perpendicularity with the horizontalbase. The bevel adjustment allows the saw blade, cutter or other workingdevice to move angularly with respect to the horizontal base whilemaintaining perpendicularity with the vertical fence. At times it may bedesirable to cut a combination miter angle and bevel angle bysimultaneously adjusting the angularity of the blade with respect toboth the horizontal base and the vertical fence.

Once the saw blade, cutter or other working device has been adjusted tothe desired position with respect to the horizontal base and thevertical fence, locking mechanisms for the miter and bevel adjustmentmust be activated in order to prohibit movement of the saw blade, cutteror other working device with respect to the base and fence while thecutting operation is performed. These locking mechanisms need to beeasily activated, adjustable and quick acting in order to optimize theefficiency of the cutting apparatus and provide convenience to theoperator of the apparatus.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved bevel lock isemployed in a power tool. The power tool comprises a table. A shaft isfixedly secured to the table. The power tool also has a support housingsupporting a motor and a working tool driven by the motor. The supporthousing is disposed on the shaft adjacent to the table and is axiallymovable along the shaft and laterally pivotable about an axis ofrotation. In addition, the power tool has a locking mechanism forlocking the support housing at a predetermined lateral position, whereinthe locking mechanism comprises a handle disposed on the shaft. Thehandle is rotatable in two directions with respect to the shaft, suchthat rotation of the handle on the shaft urges the support housing intolocking contact with the table.

Other advantages and objects of the present invention will becomeapparent to those skilled in the art from the subsequent detaileddescription, appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings which illustrate the best mode presently contemplatedfor carrying out the present invention:

FIG. 1 is a front perspective view of a sliding compound miter saw inaccordance with the present invention;

FIG. 2 is a front elevational view of the sliding compound miter sawshown in FIG. 1;

FIG. 3 is a rear elevational view of the sliding compound miter sawshown in FIGS. 1 and 2;

FIG. 4 is a side elevational view of the sliding compound miter sawshown in FIGS. 1 through 3;

FIG. 5 is an exploded perspective view of a first embodiment of thebevel stop mechanism in accordance with the present invention;

FIG. 6 is an assembled perspective view, partially in cross-section ofthe first embodiment of the bevel stop mechanism shown in FIG. 5;

FIG. 7 is a cross-sectional side view of the first embodiment of thebevel stop mechanism shown in FIG. 5;

FIG. 8 is an end view of the base or table assembly illustrating a firstembodiment of the adjustment feature provided for the bevel stopmechanism shown in FIG. 5;

FIG. 9 is an exploded perspective view of a second embodiment of thebevel stop mechanism in accordance with the present invention;

FIG. 10 is a cross-sectional side view of the second embodiment of thebevel stop mechanism shown in FIG. 9;

FIG. 11 is a cross-sectional side view of a third embodiment of thebevel stop mechanism;

FIG. 12 is a cross-sectional side view of a fourth embodiment of thebevel stop mechanism;

FIG. 13 is a cross-sectional side view of a fifth embodiment of thebevel stop mechanism;

FIG.s 14A and 14B are cross-sectional side views of a sixth and seventhembodiment of the bevel stop mechanism;

FIG. 15 is a cross-sectional rear view along line A--A of FIG. 14B;

FIG. 16 is a top view of the shaft along line B--B of FIG. 15;

FIG. 17 is a cross-sectional side view of a eighth embodiment of thebevel stop mechanism;

FIG. 18 is a cross-sectional rear view along line C--C of FIG. 17; and

FIG. 19 is a cross-sectional side view of an ninth embodiment of thebevel stop mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in which like reference numerals designatelike or corresponding parts throughout the several views, there is shownin FIGS. 1 through 4 an exemplary sliding compound miter sawincorporating a bevel stop mechanism according to the present invention,shown merely for the purposes of illustration, and designated generallyby the reference numeral 10. One skilled in the art will readilyrecognize from the following description, taken in conjunction with theaccompanying drawings and claims, that the principles of the presentinvention are equally applicable to sliding compound miter saws,compound miter saws, chop saws, radial arm saws, table saws, jigsaws,scroll saws, or other saws of types other than that shown for purposesof illustration in the drawings. Similarly, one skilled in the art willreadily recognize that the principles of the bevel stop mechanismaccording to the present invention are also applicable to other types ofpowered or unpowered equipment for performing an operation on aworkpiece. Such equipment includes, but is not limited to, dado saws,spindle shapers or sanders, or other types of powered or unpowereddevices that would benefit from the cam locking mechanism of the presentinvention.

Referring primarily to FIGS. 1 through 4, sliding compound miter saw 10comprises a base assembly 12, a table assembly 14, a unique housingassembly 16, a saw blade 18, a blade guard 20, a motor 22 drivinglyconnected to saw blade 18, a handle 24 and a fence assembly 26. Tableassembly 14 is secured to base assembly 12 such that it can be rotatedin order to provide adjustment for miter cutting. The rotation of tableassembly 14 changes the angle of saw blade 18 relative to fence assembly26 but maintains the perpendicularity of saw blade 18 with tableassembly 14. A locking mechanism 28 can be activated in order to locktable assembly 14 to base assembly 12.

Housing assembly 16 is secured to table assembly 14 such that it can bepivoted with respect to table assembly 14 in order to provide adjustmentfor bevel cutting. As can be appreciated by one skilled in the art, theadjustments for mitering and beveling can be separate or they can beadjusted simultaneously in order to provide a compound miter and bevelcut. The pivoting of housing assembly 16 changes the angle of saw blade18 relative to table assembly 14 but maintains the perpendicularity ofsaw blade 18 with respect fence assembly 26. A locking mechanism 30 canbe activated in order to lock housing assembly 16 to table assembly 14at any desired bevel angle.

Referring to FIGS. 1 through 5, housing assembly 16 includes supporthousing 32, which mounts a pair of support arms 34 for sliding movementwith respect to housing 32. Saw blade 18, blade guard 20, motor 22 andhandle 24 are all mounted to a drive housing 36 which is pivotablysecured to support arms 34. The pivoting of drive housing 36 downwardtowards table assembly 14 operates to open blade guard 20 and cut aworkpiece which is supported by table assembly 14 and fence assembly 26.The sliding movement of support arm 34 relative to housing 32 permitsdrive housing 36 and thus saw blade 18 to be pulled through theworkpiece when the size of the workpiece exceeds the cutting width ofsaw blade 18.

Referring now to FIGS. 5 through 8, support housing 32 is pivotablysupported with respect to table assembly 14 on a steel shaft 40 which issecured to table assembly 14 and extends rearwardly from table assembly14 to define a pivot axis 42 for support housing 32. Shaft 40 isinserted into a complimentary bore 44 located within table assembly 14and is secured in place using a cross pin 46 which extends through abore 47 extending through shaft 40 and a corresponding set of bores 48located within table assembly 14 and being generally perpendicular toand extending into bore 44. The end of shaft 40 opposite to the enddefining bore 46 includes a threaded stub 50 for retaining and adjustinglocking mechanism 30 as will be described later herein.

Persons skilled in the art will recognize that the shaft 40 can be fixedto the table assembly 14 using other means. For example, the shaft 40can be soldered or screwed unto the table assembly 14. Similarly, theshaft 40 can be built into the table assembly 14 as a fixed casting.

Locking mechanism 30 comprises a cam 52, a handle 54, a thrust bearing55, a plurality of washers 56 and a locknut 58. Once support housing 32is slidingly and pivotably received on shaft 40, cam 52 is slidinglypositioned on shaft 40 adjacent support housing 32. Cam 52 includes aD-shaped through bore 60 which mates with a corresponding D-shapedportion 62 of shaft 40 such that cam 52 is allowed to move axially alongportion 62 of shaft 40 but rotation of cam 52 with respect to shaft 40is prohibited. Cam 52 further includes an angular camming surface 64having a plurality of ramps which is located on the radial surface ofcam 52 which is opposite to support housing 32. Camming surface 64 isdesigned to mate with handle 54 as will be described later herein.

Handle 54 is slidingly and rotatably positioned on shaft 40 adjacent toand outboard of cam 52. Handle 54 includes an angular camming surface 66having a plurality of ramps which mates with angular camming surface 64on cam 52. Support housing 32, cam 52 and handle 54 are retained onshaft 40 by thrust washer 55, the plurality of washers 56 and locknut 58which is threadingly received on stub 50 of shaft 40.

When angular camming surface 64 and angular camming surface 66 are infull contact with each other as shown in FIG. 7, support housing 32 isfree to pivot on shaft 40 to change the bevel angle of saw blade 18.Once the desired bevel angle has been set, handle 54 is rotated withrespect to shaft 40. Rotation of handle 54 mis-aligns camming surfaces64 and 66 pushing support housing 32 and cam 52 axially along shaft 40.Support housing 32 contacts table assembly 14 and continued rotation ofhandle 54 forces support housing 32 into table assembly 14 locking thetwo components together. The locking of the two components together canbe accomplished by rotating handle 54 in either a clockwise or a counterclockwise direction on order to misalign camming surfaces 64 and 66.This bi-directional locking ability of handle 54 simplifies theadjustment of the bevel angle on opposite sides of center. An indicatorplate 68 is bolted to support housing 32 to allow the user to set aspecific bevel angle. Indicator plate 68 is provided with a pair ofslots which allow for the zero adjustment of plate 68 as is well knownin the art.

Referring to FIGS. 9 and 10, a second embodiment of the bevel lockingmechanism is illustrated. Unlike the prior embodiment, the handle 54 isprovided with a camming surface 66a which mates with camming surface 64aon cam 52a. As shown in FIG. 9, the camming surface 66a is provided withpeaks 66p and valleys 66v. Camming surface 64a has corresponding peaksand valleys in order to mate with camming surface 66a. Having themultiple peaks and valleys helps in evenly distributing the cammingforce. Nevertheless, the arrangement and operation of the secondembodiment is similar to the one illustrated in FIGS. 5 to 7. Inaddition, the operator is still able to lock the housing 32 and thetable assembly 14 together by rotating handle 54 in either a clockwiseor a counter clockwise direction.

Referring to FIG. 11, a third embodiment of the bevel locking mechanismis illustrated. The handle 54 is provided with a camming surface.Preferably, this camming surface is similar to camming surface 66a asshown in FIG. 9 and described above. In addition, cam 52b is providedwith camming surface 64b. As shown in FIG. 11, the camming surface 64bis provided with at least one protrusion, or bump, 64ba. Rotation of thehandle 54 mis-aligns camming surfaces 64b and 66a, so that peaks 66pcontact bumps 64ba. The contact between the peaks 66p and bumps 64bapush support housing 32 and cam 52b axially along shaft 40, lockinghousing and table assembly 14 together. and valleys 66v. Camming surface64a has corresponding peaks and valleys in order to mate with cammingsurface 66a. Nevertheless, the arrangement and operation of the thirdembodiment is similar to the one illustrated in FIGS. 5 to 7.Accordingly, the operator is able to lock the housing 32 and the tableassembly 14 together by rotating handle 54 in either a clockwise or acounter clockwise direction.

A person skilled in the art will recognize that the bumps 64ba can bereplaced by balls 64bb, disposed within holes 64bh within the cam 52c,as shown in FIG. 12. Nevertheless, the arrangement and operation of thisfourth embodiment is similar to the one illustrated in FIGS. 5 to 7.Accordingly, an operator is able to lock the housing 32 and the tableassembly 14 together by rotating handle 54 in either a clockwise or acounter clockwise direction.

A person skilled in the art will also recognize that the cam 52i can beintegrated with the support housing 32, as shown in FIG. 13. This isespecially advantageous as less parts are necessary for manufacture.Nevertheless, the arrangement and operation of this fourth embodiment issimilar to the one illustrated in FIGS. 5 to 7. Accordingly, an operatoris able to lock the housing 32 and the table assembly 14 together byrotating handle 54 in either a clockwise or a counter clockwisedirection.

FIGS. 14A to 16 illustrate a sixth and seventh embodiment of the bevellock mechanism. In both embodiments, the shaft 40 is provided with a"double screw" portion 102. As shown in FIG. 16, on one side of thedouble screw portion 102, a set of threads 101a are disposed thereon ina first orientation. In addition, on the other side of the double screwportion 102, a second set of threads 101b are disposed thereon in asecond orientation. The threads 101a and 101b intersect to form V-shapedthreads 101. Preferably, the resulting threads 101 will have a lowpitch, so that more travel along the axis of the rod can be obtainedwith a smaller amount of rotation.

The handle 54a has protrusions 105 to engage the threads 101 as shown inFIG. 14A. These protrusions 105 slide along the threads 101, handle 54ato travel along shaft 40. This in turn forces the handle 54a towards thesupport housing 32, thus clamping the support housing 32 in placebetween handle 54a and table assembly 14. Accordingly, the rotationalmotion of handle 54a is translated into a linear motion along shaft 40,causing the clamping action.

As shown in FIGS. 14A and 14B, the protrusions 105 preferably match theprofile of the threads 101, allowing travel along threads 101.Accordingly, if the thread 101 is rounded, the protrusions 105 arepreferably rounded. Preferably, the protrusions 105 are disposed on abutton 100 as shown in FIG. 14B. It is also advantageous to provide aspring 104 to bias the button 100 into contact with the double screwportion 102. Accordingly, in order to install handle 54a, an operatorneed only push gripping portion 101a of the button 100, slide the handle54a along the shaft 40, and release button 100.

People skilled in the art will recognize that means other than thespring 104 will also allow easy installation and removal of handle 54a.For example, as shown in FIG. 19, the handle 54a may include a threadengaging portion 54b, held in place by a plug 54c. Accordingly, in orderto install handle 54a, an operator need only slide the handle 54a alongthe shaft 40 and insert the thread engaging portion 54b, so that itengages the threads 101. The operator can then insert the plug 54c tohold the thread engaging portion 54b in place.

FIGS. 17 and 18 show yet another embodiment of the bevel lock mechanism.Unlike in the previous embodiments, the locking shaft and the pivot axisare not the same. As shown in FIG. 17, support housing 32 is pivotablysupported with respect to table assembly 14 on a shaft 110 which isfixedly secured to table assembly 14 via threads 111. Persons skilled inthe art will recognize that other means for fixing the shaft 110 to thetable assembly 14 are available. The shaft 110 extends rearwardly fromtable assembly 14 to define a pivot axis 142 for support housing 32.Preferably, the shaft 110 has a threaded portion 112. A thrust bearing551, a washer 561 and a locknut 581 are disposed on the shaft 110 inorder to retain the housing 32.

In addition, locking shaft 401 is inserted into a complimentary bore 441located within table assembly 14 and is secured in place using a crosspin 461 which extends through a bore 471 extending through shaft 401 anda corresponding set of bores 481 located within table assembly 14 andbeing generally perpendicular to and extending into bore 441. The end ofshaft 401 opposite to the end defining bore 461 includes a threaded stub501 for retaining and adjusting a locking mechanism 30, such as the onesdescribed above. As shown in FIG. 18, a slot 140 is provided in thetable assembly 14. The shaft 401 is disposed through the slot 140 sothat, as the bevel angle is changed, the shaft 401 can travel along theslot 140.

Persons skilled in the art will see that the locking shaft 401 issubstantially parallel to shaft 110. However, those persons shouldrecognize that the disclosed embodiment is for exemplary purposes onlyand that the shafts 401 and 1 10 need not be parallel to each other.

As shown in FIG. 17, the locking mechanism 30 shown in FIGS. 5 to 7 canbe disposed on the locking shaft 401 and used as described above.However, persons skilled in the art will recognize that any of thedifferent embodiments described above for the locking mechanism can beused instead.

The above detailed description describes different embodiments of thepresent invention. Persons skilled in the art may recognize otheralternatives to the means disclosed herein, such as using a knob insteadof handle 54. However, all these additions and/or alterations areconsidered to be equivalents of the present invention.

What is claimed is:
 1. A device for performing working operations on aworkpiece, said device comprising:a table; a shaft fixedly secured tosaid table, said shaft having an axis; a support housing supporting amotor and a working tool driven by said motor, said support housingbeing disposed on said shaft adjacent to said table, said supporthousing being axially movable along said shaft and being laterallypivotable about an axis of rotation; and a locking mechanism for lockingthe support housing at a predetermined lateral position, wherein saidlocking mechanism comprises a handle disposed on said shaft, said handlebeing rotatable in two directions with respect to said shaft, such that,upon rotation of said handle in both directions from a neutral positionon said shaft, the handle urges said support housing into contact withsaid table.
 2. The device according to claim 1, wherein said lockingmechanism further comprises a cam disposed on said shaft between saidhandle and said support housing.
 3. The device according to claim 1,wherein the shaft axis is substantially parallel to the axis ofrotation.
 4. The device according to claim 1, wherein the shaft axiscorresponds to the axis of rotation.
 5. The device according to claim 1,wherein the shaft has a first surface having a first thread disposedthereon in a first orientation, and a second surface having a secondthread disposed thereon in a second orientation, said first and secondthread intersect forming a V-shaped thread.
 6. The device according toclaim 1, wherein said device is a compound miter saw.
 7. An apparatusfor moving a member axially along a shaft, said apparatus comprising:afirst shaft surface having a first thread disposed thereon in a firstorientation; a second shaft surface having a second thread disposedthereon in a second orientation, wherein said first and second threadintersect forming a V-shaped thread portion; a handle disposed on saidshaft, said handle having a thread engaging portion contacting saidV-shaped thread portion and being rotatable in two directions withrespect to said shaft, such that rotation of said handle in bothdirections from a neutral position on said shaft causes axial movementalong said shaft of both said handle and said member.
 8. A method foroperating a device comprising a table, a shaft fixedly secured to saidtable, said shaft having an axis, a support housing supporting a motorand a working tool driven by said motor, said support housing beingdisposed on said shaft adjacent to said table, said support housingbeing axially movable along said shaft and being laterally pivotableabout an axis of rotation, and a locking mechanism for locking thesupport housing at a predetermined lateral position, wherein saidlocking mechanism comprises a handle disposed on said shaft, said handlebeing rotatable in two directions with respect to said shaft, saidmethod comprising the steps of:adjusting lateral position of saidsupport housing; and rotating said handle in one of said two directions;wherein upon rotation of said handle in both directions from a neutralposition on said shaft, the handle urges said support housing intocontact with said table.
 9. The apparatus of claim 7, wherein saidapparatus is incorporated in a device for performing working operationson a workpiece.
 10. The apparatus of claim 9, wherein the devicecomprising a table with the shaft fixedly secured thereto the table, theshaft having an axis; andthe member being a support housing supporting amotor and a working tool driven by the motor, the support housing beingdisposed on the shaft adjacent to the table, the support housing beingaxially movable along the shaft and being laterally pivotable about anaxis of rotation.
 11. The apparatus of claim 10, wherein the handlecontacts the support housing.
 12. The apparatus of claim 10, wherein theshaft axis corresponds to the axis of rotation.
 13. The apparatus ofclaim 10, wherein said device is a compound miter saw.